ChangeLog:

[pf3gnuchains/gcc-fork.git] / gcc / varpool.c

diff --git a/gcc/varpool.c b/gcc/varpool.c
index 90a9ace..40decfc 100644 (file)
--- a/gcc/varpool.c
+++ b/gcc/varpool.c
@@ -1,5 +1,5 @@
 /* Callgraph handling code.
-   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2010
    Free Software Foundation, Inc.
    Contributed by Jan Hubicka
 
@@ -30,7 +30,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "hashtab.h"
 #include "ggc.h"
 #include "timevar.h"
-#include "debug.h" 
+#include "debug.h"
 #include "target.h"
 #include "output.h"
 #include "gimple.h"
@@ -57,21 +57,21 @@ struct varpool_node *varpool_nodes;
 
 /* Queue of cgraph nodes scheduled to be lowered and output.
    The queue is maintained via mark_needed_node, linked via node->next_needed
-   pointer. 
+   pointer.
 
    LAST_NEEDED_NODE points to the end of queue, so it can be
    maintained in forward order.  GTY is needed to make it friendly to
    PCH.
- 
+
    During compilation we construct the queue of needed variables
    twice: first time it is during cgraph construction, second time it is at the
    end of compilation in VARPOOL_REMOVE_UNREFERENCED_DECLS so we can avoid
    optimized out variables being output.
-   
-   Each variable is thus first analyzed and then later possibly output.  
+
+   Each variable is thus first analyzed and then later possibly output.
    FIRST_UNANALYZED_NODE points to first node in queue that was not analyzed
    yet and is moved via VARPOOL_ANALYZE_PENDING_DECLS.  */
-   
+
 struct varpool_node *varpool_nodes_queue;
 static GTY(()) struct varpool_node *varpool_last_needed_node;
 static GTY(()) struct varpool_node *varpool_first_unanalyzed_node;
@@ -207,6 +207,8 @@ varpool_enqueue_needed_node (struct varpool_node *node)
 void
 varpool_mark_needed_node (struct varpool_node *node)
 {
+  if (node->alias && node->extra_name)
+    node = node->extra_name;
   if (!node->needed && node->finalized
       && !TREE_ASM_WRITTEN (node->decl))
     varpool_enqueue_needed_node (node);
@@ -228,6 +230,12 @@ varpool_reset_queue (void)
 bool
 decide_is_variable_needed (struct varpool_node *node, tree decl)
 {
+  /* We do not track variable references at all and thus have no idea if the
+     variable was referenced in some other partition or not.  
+     FIXME: We really need address taken edges in callgraph and varpool to
+     drive WPA and decide whether other partition might reference it or not.  */
+  if (flag_ltrans)
+    return true;
   /* If the user told us it is used, then it must be so.  */
   if ((node->externally_visible && !DECL_COMDAT (decl))
       || node->force_output)
@@ -383,9 +391,22 @@ varpool_assemble_decl (struct varpool_node *node)
       assemble_variable (decl, 0, 1, 0);
       if (TREE_ASM_WRITTEN (decl))
        {
+         struct varpool_node *alias;
+
          node->next_needed = varpool_assembled_nodes_queue;
          varpool_assembled_nodes_queue = node;
          node->finalized = 1;
+
+         /* Also emit any extra name aliases.  */
+         for (alias = node->extra_name; alias; alias = alias->next)
+           {
+             /* Update linkage fields in case they've changed.  */
+             DECL_WEAK (alias->decl) = DECL_WEAK (decl);
+             TREE_PUBLIC (alias->decl) = TREE_PUBLIC (decl);
+             DECL_VISIBILITY (alias->decl) = DECL_VISIBILITY (decl);
+             assemble_alias (alias->decl, DECL_ASSEMBLER_NAME (decl));
+           }
+
          return true;
        }
     }
@@ -507,4 +528,40 @@ add_new_static_var (tree type)
   return new_node->decl;
 }
 
+/* Attempt to mark ALIAS as an alias to DECL.  Return TRUE if successful.
+   Extra name aliases are output whenever DECL is output.  */
+
+bool
+varpool_extra_name_alias (tree alias, tree decl)
+{
+  struct varpool_node key, *alias_node, *decl_node, **slot;
+
+#ifndef ASM_OUTPUT_DEF
+  /* If aliases aren't supported by the assembler, fail.  */
+  return false;
+#endif
+
+  gcc_assert (TREE_CODE (decl) == VAR_DECL);
+  gcc_assert (TREE_CODE (alias) == VAR_DECL);
+  /* Make sure the hash table has been created.  */
+  decl_node = varpool_node (decl);
+
+  key.decl = alias;
+
+  slot = (struct varpool_node **) htab_find_slot (varpool_hash, &key, INSERT);
+
+  /* If the varpool_node has been already created, fail.  */
+  if (*slot)
+    return false;
+
+  alias_node = GGC_CNEW (struct varpool_node);
+  alias_node->decl = alias;
+  alias_node->alias = 1;
+  alias_node->extra_name = decl_node;
+  alias_node->next = decl_node->extra_name;
+  decl_node->extra_name = alias_node;
+  *slot = alias_node;
+  return true;
+}
+
 #include "gt-varpool.h"